Pulsed Voltammetric Techniques

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Pulsed Voltammetric Methods. Pulsed Voltammetric Techniques. Typical Set up for Polarography. Pulsed Voltammetric Methods. DC Polarography with Dropping Mercury Electrode (DME). Pulsed Voltammetric Methods. Sample-and-Hold or Tast (sampled-current) Voltammetry. D E. E. t. t. - PowerPoint PPT Presentation


<ul><li><p>Pulsed Voltammetric TechniquesTypical Set up for PolarographyPulsed Voltammetric Methods</p></li><li><p>DC Polarography with Dropping Mercury Electrode (DME)Pulsed Voltammetric Methods</p></li><li><p>Sample-and-Hold or Tast (sampled-current) VoltammetryPulsed Voltammetric MethodsEttDECurrent is sampled late in the drop life, so faradaic current is minimized versus near onset.LOD ~ 10-5 M</p></li><li><p>Normal Pulse (NPV or NPP) vs. Tast VoltammetryPulsed Voltammetric MethodsCurrent sampled and held.If &gt; 5RsCd (~0.05-15 ms), icharging is almost insignificant.LOD ~ 10-5 -10-6M</p></li><li><p>DPVNPVDifferential Pulse (DPV) vs. Normal Pulse VoltammetryPulsed Voltammetric MethodsSmall ifaradaicwhen away from E0</p><p>Large ifaradaic when near E0LOD ~ 10-6 -10-7 M</p></li><li><p>NPVDPVOsteryoungSquareWaveVoltammetryComparison of Excitation Waveforms for Pulsed VoltammetriesPulsed Voltammetric Methods</p></li><li><p>Osteryoung Square Wave VoltammetryPulsed Voltammetric MethodsLOD ~ 10-8 M</p></li><li><p>Osteryoung Square Wave VoltammetryPulsed Voltammetric Methods</p></li><li><p>Stripping Analysis Coupled to DPV - DPASVip = 0.138 Qmetal/tpulse-width~50-nm thick Hg film on Glassy Carbon (vitreous) electrode by electrodeposition from acidic Hg2+DPVDeposit M0Limit of Detection of ~0.005 ppmPulsed Voltammetric Methods</p></li></ul>